Igniter mechanism for explosive-engines.



No. 756,961. I PATENTED APR. 12, 1904. N. E. HILDRETH.

IGNITEE MEGHANISM FOR EXPLOSIVB ENGINBS.

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No. 756,961. PATENTBD APR. 12, 1904.

N E. HILDRETH.

IGNITER MECHANI SM FOREXPLOSIVB ENGINES. APPLIOATION PILED JUNE 19,1902.

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UNITED S-*rarns Patented April 12, 1904.

NED E. HILDRETH, OF LANSING, MICHIGAN.

IGNITER NIECHANISIVI FO R EXPLOSIVE-ENGINES..

SPECIFICATION forming part of Letters Patent No. *756,961, dated April12, 1904.

Application filed June 19,1902. Serial No. 112,279. No model.)

To roll whom it nuy concern: i

Be it known that I, NED E. HILDRETH, a citizen of the United States,residing at Lansing, in the county of Ingham, State of Michigan, haveinvented certain new and useful Improvements in Igniter Mechanisrn forExplosive-Engines; and I do declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings, and to the figures ofreference marked thereon, which form a part of this specification. r

This invention relates to an igniter mechanism for eXplosive-engines;and it consists in the construction and arrangement of parts hereinafterfullyset forth, and pointed out particularly in the claims.

The object of the invention is to provide simple and eflicient means forexploding a charge in the combustion-chamber 'of an engine-oylinder ofthe type using a mxture of air and any of the common ignitible gases,the arrangement being such as to produce a perfect spark and to aford aregulation of the operative parts, so as to time the explosion withrespect to the movement of the piston as may be desired. i

The above object'is attained by the mechanism llustrated in theaccompanying drawings, in which Figure 1 is an elevation of a portion ofa cylinder, showing an exterior View of the igniter mechanism and aportion of the reciprocatory rod, through the medium of which saidmechanism is actuated. Fig. 2 is a verticalsection through thecombustion-chamber and cylni der, showing the igniter mechanism inelevation. .Fig. 3 is an enlarged View, partly in section, showing aportion of the reciprocatory rod and a sectional View of the tilting dogmounted thereon adapted to engage an arm of i the igniter meohanism.Fig. 4 is an enlarged end elevation of the screw-plug in which theoperative parts of the igniter are mounted. Fig. 5 is an inner endelevation thereof. Fig. 6 is a longitudinal section through the plug andoperative parts, as on line 6 6 of Fig. 4. Fig.` 7 is a detail inelevation of the operative mechanism, showing the position of parts justprevious to the causing of the spark. Fig. 8 is an enlarged sectionalview through the reciprocatory rod above the dog mounted thereon,showing the oblong opening through said dog. i

Referring to the characters of reference, l designates the cylinder, aportion of which is broken away and which preferably consists of aninner and an outer shell, between which is 'formed a water-space 2 forthe purpose of keeping down the temperature of the cylinder, as .is wellunderstood in the art, /Vithin the cylinder is a piston 3, whosereciprocatory motion is adapted to be imparted in the form of arotarylmotion to the crank-shaft by means of the pitman adapted to beconnected to the wrist-pin 4 of the piston, said pitman and crank-shaftnot being shown, as they are of the common and well-known Construction.In the end of the cylinder is the combustionchamber 5, in which thecharges of combustiblc gases are explod ed to impart an impulse to theengine through the piston, upon which said explosions act.

The explosive charges are ignitd in the combustion-chamber by means ofanelectric spark produced at predetermined intervals, according to thespeed of the engine. I The sparker comprises a suitable plug 6, whichscrews through the wall of the oylinder and projects into thecombustion-chamber and in the end of which is seated a pin 7, upon whichis journaled an oscillatory arm 8, adapted to swing in the arc of acircle upon said pin and having attached to the hub thereof one end of astifi' coiled spring 9, whose opposite end is Secured in the plug 6.Passing longitudinally through the plug 6 is a rock-shaft 10, which isjournaled in said plug and carries fixed to the outer end thereof acollar 11, having a straight face 12 standing uppermost and in the pathof the arm 8. Upon the inner end of the rock-shaft 10 isa movableelectrode 13, adapted to describe the are of a circle concentric withthe movement of said shaft. Fixed in the plug 6 and extendingtherethrough is an electrode 14, which is insulated from the plug by asleeve of suitable insulating material 15, and to the outer end of whichIOO is connected a wire 16, which leads to a battery-generator or othersource of electricity. (Not shown.) The other wire 17 from the source ofelectric energy is connected with the plug 6, as illustrated, or in anysuitable manner, so that the current will pass into the rockshaft 10 andinto the electrode 13, mounted upon the inner end thereof. The innerends of the electrodes 13 and 1 1- are pro: vided with suitablecontact-points 18, which are normally separated. Mounted upon the outerend of the rock-shaft 10 is a coiled spring 19, one end of which issecured to said shaft and the other end to the plug 6. The tension ofspring 19 is less than that of spring 9, so that normally the force ofspring 9 is eXerted to overcome that of spring 19 and to cause the fiatface 12 of the collar 11 to lie contiguous to and parallel with theunder face of the arm 8, as shown by solid lines in Fig. 1, in whichposition the electrodes are held apart and their contact-points areseparated. When the outer end of the arm 8 is raised, however, so as torelease the collar 11, spring 19 will rotate the shaft 10 and actuateelectrode 13 to bring its contact-point into engagement with that ofelectrode 14:, as shown in Fig. 6, thereby closing the electrc circuitthrough said electrodes. v The free end of the arm 8 is carried upwardlyby an arrangement hereinafter described until considerable tension isplaced upon its spring 9, when upon the release of said arm it willreturn and strike the collar ll a sharp blow upon the corner 20 thereof,as shown in Fig. i, thereby rotating the rock shaft 10 against theaction of spring 19 and separating the contacts of the electrodes,thereby producing an arc which ignites the charge in thecombustion-chamber of the engine. The contact-points of said electrodesare held separated by the force of the spring 9 until the succeedingoperation.

To provide for Operating the trip-arm 8 in a manner to cause theseparation of the contacts of the electrodes, as described, areciprocatory rod 21 is employed, which is given movement by attachmentto any movable part of the engine. (Not shown.) Upon said rod is mounteda tilting dog 22, having an aperture 23 therethrough, through' whichsaid rod passes and which is oblong at its upper end, as shown in Fig.8. Pivoted at 24 to the rod 21 is an eccentric lever 25, having theconcave bearing-faces 26 and 27. The lower end of the dog 22 rests uponthe eccentric lever and is maintained in place by the coiled-spring 28,the upper end of which is attached to said dog and the lower end to therod 21. Upon the upper end of the dog 22 is a projecting lip 29, adaptedto engage the outer end of the arm 8. Secured to the end of the cylinderis a projecting plate 30, through which the rod 21 passes. c

In the operation of this device it will be understood that the charge ofeXplosiVe vapor is drawn into the combustion-chamber and compressedtherein by the upward movement of the piston or the movement thereof inthe direction of 'the combustionchamber. The parts are so timed in theiroperation that the dog 22 on the rod 21 engages the free end of the arm8 as the piston is traveling back to compress the charge. At the timewhen the piston has reached the limit of its return stroke the dog 22will slip past the end of the arm 8, allowing said arm to be returned bythe tension .of its spring 9 and to strike the collar 11 of therock-shaft 10, as beforevdescribed, and rocks said shaft to separate thecontacts of the electrodes and produces a spark which eXplodes themixture in the combustion-chamber and gives an impulse to the engine.

It is necessary in starting motors or engines of this class, because ofthe slowness of the movement, to explode the charge at the time when thepiston has reached the limit of its in travel in order to avoid drivingthe piston back' by the force of the explosion before thecrank haspassed the in center and causing the engine to run backward. After theengine has attained speed, however, it has been found that more powercan be developed with a given quantity of eXplosive mixture if thecharge is exploded before the piston reaches the limit of its in stroke,so that the full expansive force of the charge may be obtained, themomentum of the fly-wheel of the engine serving to carry the crank pastthe center.

I control the ignition of the charge with respect to the travel of thepiston by means of the eccentric lever 25. When the parts are inposition, (shown in Fig. 1,) the dog 22 Will trip the arm 8, so as tofire the charge at the time the piston reaches the limit of its instroke, the position in which said parts are used in starting. After theengine has attained speed the eccentric lever is turned to the positionshown by dotted lines in Fig. 1 and by solid lines in Fig. 7 through themedium of its handle 31, when the dog 22 will be raised higher and willsooner engage and release the arm 8 by the same movement of the rod 21,thereby causing the spark in the combustion-chamber before the pistonhas reached the limit of its return stroke.

The oblong opening 23 in the dog through which the rod passes is toallow the upper end of the dog to recede as said dogis returned by theoperation of the rod 21 past the end of the arm 8, said dog beingrestored to its former position after passing said arm by the tension ofthe spring 28.

It will now be understood that by means of this device a charge may befired in the combustion-chamber after the piston hasreached the limit ofits inward travel when starting the engine and that after the properspeed IOO IIO

'lever the charge may be fired before the piston reaches the limit ofits inward travel at such point as may be desired, thereby developingthe highest efiiciency of the engine.

Having thus fullyset forth my invention, what I claim as new, and desireto secure by Letters Patent, is-

1. ln an igniter for explosive-engines, the combination, With theigniting mechanism, of a reciprocatory rod, a dog mounted on said rocladapted to engage and operate said igniting mechanism, saicl dog beingsliclable upon said rocl and 'aclapted to tilt thereon, and means forreturning said clog after the tilting movement, means for sliding thedog longitudinally on saicl rocl and for holding saicl clog againstlongtuclinal movement only, at two predeterminecl points.-

2. In an igniter for explosve-engines, the combination, with theigniting mechanism, of a reciprocatory rod, a dog having a centrallongtuclnal opening through which said rod passes, the shape of saidopening at the lower end of the dog being round and substantially oblongat the upper end to allow a tilting movement of the dog upon the rocl,said dog being also movable longitudnally upon said rocl and aclapteclto actuate theignting mechanism, and a spring attached thereto forrestoring t after a tilting movement.

3. In an igniter for explosive-engines, the combination with the gnitermechanism of a reciprocatory rod, the dog mounted upon said rocl to movelongituclinally thereon, said dog being aclapted to actuate the ignitermechanism, an eccentric lever pivoted to said rod and engaging the lowerend of sacl dog, whereby said clog may be adjustecl upon the rod andheld from longituclnal movement after adjustment.

4. In an gnter for eXplosive-engines, the combination with the cylinder,of a rock-shaft eXtending into the cylinder and carrying a movableelectrocle, a fixed electrode eXtenclng into the cylinder in the path ofthe movable electrode, a collar upon the end of said rockshaft, aspring-actuatecl arm adaptecl to strike said collar and rotate saidshaft to separate the electrodes, a reciprocatory rod, a dog mountecl onsaid rod to slide longitudinally and tilt transversely thereon, said dogbeing adaptecl to engage the free encl of saidlarm when moving in onedirection and to slip past said arm on the return movement, and meansfor looking said dog against longitudinal movement only, at twoprecletermined points on said rod.

In testimony whereof' I sign this specification in the presence of twowitnesses.

NED E. HILDRETH.

Witnesses:

LUTHER B. MCEWING, WILFRED E. CADY.

